Rarely seen in public, they only come out of their parent's basements to attend conventions of their favorite interests, such as Star Trek, Inuyasha, or furry porn. Fatbeards have the personality of a wood plank.

verb: To talk pedantically and at great length about minutiae in nerd and geek culture. Especially concerning tabletop games such as Dungeons & Dragons or Warhammer Fantasy Battles. Typically used as a pejorative.